| 摘要 |
PURPOSE:To enable the cut of an elastic plate to open when the internal pressure of a lead storage battery is high and to close when the internal pressure is low by causing the outer area of the elastic plate to more easily expand and deform than its inner area. CONSTITUTION:An exhaustion valve for a negative electrode absorption type sealed battery is formed by interposing an elastic plate 1 made of rubber or the like and having a pin-hole or cut 2 between a lower frame 3, which has a hole 3' having a smaller diameter and opening into the internal space of the battery, and an upper frame 5, which has a larger diameter and opening into external air. Due to the difference in diameter between the openings 3' and 5', the outer area of the elastic plate 1 easily expands and deforms and the inner area hardly expands and deforms, Therefore, the cut 2 opens when the internal pressure of the battery is high and the cut 2 is closed when the internal pressure is low. As a result, external air is prevented from permeating into the battery, thereby improving its reliability. |
